Turbine systems are widely utilized in fields such as power generation. For example, a conventional gas turbine system includes a compressor, a combustor, and a turbine. During operation of the gas turbine system, various components in the system are subjected to high temperature flows, which can cause the components to fail. Since higher temperature flows generally result in increased performance, efficiency, and power output of the gas turbine system, the components that are subjected to high temperature flows must be cooled to allow the gas turbine system to operate at increased temperatures.
Various strategies are known in the art for cooling various gas turbine system components. For example, a cooling medium may be routed from the compressor and provided to various components. The cooling medium may be utilized to cool various components, such as turbine components.
Buckets are one example of a hot gas path component that must be cooled. For example, various parts of the bucket, such as the airfoil, the platform, the shank, and the dovetail, are disposed in a hot gas path and exposed to relatively high temperatures, and thus require cooling. Various cooling passages and cooling circuits may be defined in the various parts of the bucket, and cooling medium may be flowed through the various cooling passages and cooling circuits to cool the bucket.
In many known buckets, one or more main cooling circuits may be defined in a main body, which typically includes an airfoil and shank. An additional cooling circuit may be defined in the platform. During casting of the bucket, the core components that form these circuits typically remain separate. However, such circuits must generally be in fluid communication in a finished, operable bucket. Thus, after casting, a passage is typically drilled or otherwise formed from the exterior surface of the bucket into the body. The passage extends through and connects the main cooling circuits and platform cooling circuits.
In order to prevent cooling medium from escaping through this passage during operation of the bucket, a plug is typically inserted in the passage. However, known plugs have a variety of disadvantages. For example, many known plugs block any fluid communication between cooling circuits, and include passages within the plug to provide this fluid communication. The use of such passages can cause inefficient cooling by improperly restricting the cooling medium and forcing the cooling medium to follow the paths of such passages. Other known plugs include orientation features, and only operate properly when the plugs are inserted into the passages at proper orientations.
Thus, an improved plug and bucket assembly for a turbine system is desired in the art. Specifically, a plug and bucket system with improved features for providing fluid communication between various cooling circuits would be advantageous.